Prolonged cultivation of embryos in vitro (LTC-BS — Long Term Cultivation to the Blastocyst Stage) is a process whose main purpose is to maintain the normal development and viability of embryos in General, before planting them in the uterine cavity in IVF. The process is fairly short and takes only 6 days. After that, the embryo should be planted into the uterus to attach to the endometrium.
What is this kind of procedure?
Prolonged cultivation of embryos is inherently a high-tech and rather complex process that requires a special, well-equipped laboratories and expensive equipment. In view of this feature, not all centres carrying out IVF and planning a pregnancy, provide such procedure.
This method involves culturing embryos to the blastocyst stage. Previously used methods suggested transplantation of the embryo in the woman’s body is still under the crushing, i.e. 2-3 days. This drastically reduced the success of IVF procedures and the embryo transfer had to be repeated many times.
The transition to the cultivation of embryos in vitro has become possible technological breakthrough in the field of embryology, with special developments in the field of reproductive medicine. In this method, used in the leading reproductive clinics around the world, suggests a more prolonged contact with the embryo specific media (SICM/SIBM and Assist Embryo/Blast Assist).
It is also worth noting that this technique could not exist without the use of a special device – multi-gas incubator. It fits several zygotes together with a nutrient medium. After 4-6 days, the specialists remove the blastocyst from the device and assess its viability. According to statistics, about 60-70% of eggs fertilized during IVF, it is possible to obtain normal embryos.
What are the advantages of extended embryo culture?
This method of IVF makes it possible, in the first place to improve the quality of selection (of selection) and used for transplants, only embryos having sufficiently high, the so-called implantation potential. In simple words, the application of this method greatly enhanced the probability of pregnancy after IVF.
In addition, among the other advantages of extended embryo culture is usually called:
- the decrease in the number of chromosomal abnormalities in embryos that can be planted at the blastocyst stage;
- this method is more physiological compared with the transfer of the embryo up to 3 days;
- during prolonged cultivation enough to fit into the cavity of the uterus 1-2 of the embryo, because the likelihood of their retention and development is very high;
- significantly reduced the risk of developing such complications as ectopic pregnancy.
What are the disadvantages of this method?
Having dealt with the fact that it is long-term cultivation of sex cells (gametes) and embryos, describing the advantages of this method of IVF, you need not forget about the disadvantages of this method.
The first is the fact that not all cultured embryos grow to the blastocyst stage, in most cases, only 50% of them reaches this stage of development. Considering this feature, this method is possible only if to 3 day cultivation of the embryos, they will be at least 4. With fewer the probability of getting at least one normal that have reached the blastocyst stage, is very low.
The second disadvantage is that even if the embryo reaches necessary for the transplantation stage of development, it does not give 100% guarantee that implantation will be successful and the pregnancy.